Dyes are priority pollutants, commonly found at significant concentrations in textile effluents. The presence of dyes stuffs in wastewater can cause severe problems to aquatic life and human beings. Therefore, the removal of dyes from wastewater is important in order to minimize their hazardous effects on the environment. One way of removing dyes is to use nanosized manganese oxides (MnOs). To date, there has been much work reported on the use of nanosized MnOs as sorbents for dyestuffs. They are promising sorbents for commercial use due to their amorphous nature, high specific surface areas (SSA), mesoporous structure, and low to the moderate point of zero charge (pHPZC). This review summarizes the toxicity and recent advances for removing dyes from wastewater using nanosized MnO sorbents. The article also describes the various experimental parameters necessary for adsorption optimization, such as adsorption time, pH, initial dye concentration, amount of sorbent and temperature. Adsorption mechanisms investigated by various modeling approaches are also discussed. In particular, it was observed that much work has been reported on the use of birnessite and its composites for dye removal. There are many papers reporting on the use of MnO in batch mode dye removal, but very few that report on the use of MnO in continuous column removal systems. Therefore, there is still a considerable need for further research to develop effective and economical large scale MnO column systems for commercial use.

1. Contents lists available at ScienceDirect
Journal of Water Process Engineering
journal homepage: www.elsevier.com/locate/jwpe
Removal of dye from polluted water using novel nano manganese oxide-
based materials
Md. Aminul Islama,b,⁎
, Imran Alic
, S.M. Abdul Karimb
, Md. Shakhawat Hossain Firozd
,
Al-Nakib Chowdhuryd
, David W. Mortona
, Michael J. Angovea,⁎
a
Colloid and Environmental Chemistry (CEC) Research Laboratory, Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Sciences (LIMS),
La Trobe University, P.O. Box 199, Bendigo, VIC, 3552, Australia
b
Department of Arts and Sciences, Faculty of Engineering, Ahsanullah University of Science and Technology (AUST), Dhaka, 1208, Bangladesh
c
Department of Chemistry, Jamia Millia Islamia, New Delhi 1100025, India
d
Department of Chemistry, Faculty of Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh
A R T I C L E I N F O
Keywords:
Dye removal
Nano manganese oxide sorbents
Optimization
Adsorption
Wastewater
A B S T R A C T
Dyes are priority pollutants, commonly found at significant concentrations in textile effluents. The presence of
dyes stuffs in wastewater can cause severe problems to aquatic life and human beings. Therefore, the removal of
dyes from wastewater is important in order to minimize their hazardous effects on the environment. One way of
removing dyes is to use nanosized manganese oxides (MnOs). To date, there has been much work reported on the
use of nanosized MnOs as sorbents for dyestuffs. They are promising sorbents for commercial use due to their
amorphous nature, high specific surface areas (SSA), mesoporous structure, and low to the moderate point of
zero charge (pHPZC). This review summarizes the toxicity and recent advances for removing dyes from waste-
water using nanosized MnO sorbents. The article also describes the various experimental parameters necessary
for adsorption optimization, such as adsorption time, pH, initial dye concentration, amount of sorbent and
temperature. Adsorption mechanisms investigated by various modeling approaches are also discussed. In par-
ticular, it was observed that much work has been reported on the use of birnessite and its composites for dye
removal. There are many papers reporting on the use of MnO in batch mode dye removal, but very few that
report on the use of MnO in continuous column removal systems. Therefore, there is still a considerable need for
further research to develop effective and economical large scale MnO column systems for commercial use.
1. Introduction
Water pollution has become a serious problem in an era of rapid
population growth, climate change, urbanization, and industrialization.
The main groups of environmental pollutants commonly encountered
are metal ions, metalloids/anions, organic dyes, pharmaceuticals, pes-
ticides, natural organic matters, and aromatic compounds [1]. The
enormous use of dyes in many industries such as paint, textile, tannery,
paper, leather, rubber, cosmetics, and plastics has resulted in the re-
lease of large amounts of colored toxic effluent and contaminated sur-
face groundwater [2,3]. About 10,000 types of commercial dyes are
commonly used with around 7 × 105
tonnes of dyestuffs produced
annually [4]. Around 2% of them are released in effluents [4]. These
dyestuffs also have a wide range of physical, chemical, and tox-
icological properties [5]. Responsible disposal of these dyes is a big
challenge with more effective/economically dye effluent treatment
processes required to be developed. This task is challenging, as the dye
concentrations in effluent water need to be very low before releasing
into the environment. Dyestuffs are susceptible to heat, chemical re-
agent and have the capability to generate mutagens and cancer. The
dyes present in water effect different aquatic lives [5,6]. Therefore, the
removal of dyes from effluents before their discharge into the aquatic
environment is of great demand.
Textile industries produce large volumes of dye effluents, because of
the high amounts of water used in dyeing processes [7]. A number of
different treatment methods for dye removal from effluent water have
been investigated. These are, chemical oxidation [8], adsorption
[1,9–11], chemical reduction [12], photo-degradation [13], electro-
chemical oxidation [14,15], coagulation-flocculation [16], membrane
separation [17,18], Fenton oxidation [19] and biological methods [20].
https://doi.org/10.1016/j.jwpe.2019.100911
Received 26 June 2019; Received in revised form 30 July 2019; Accepted 6 August 2019
⁎
Corresponding authors at: Colloid and Environmental Chemistry (CEC) Research Laboratory, Department of Pharmacy and Biomedical Sciences, La Trobe Institute
for Molecular Sciences (LIMS), La Trobe University, P.O. Box 199, Bendigo, VIC, 3552, Australia.
E-mail addresses: aminul.chem.as@aust.edu (Md. A. Islam), andm.angove@latrobe.edu.au (M.J. Angove).
Journal of Water Process Engineering 32 (2019) 100911
2214-7144/ Crown Copyright © 2019 Published by Elsevier Ltd. All rights reserved.
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